Chapter 1. Background
The aim of the present chapter is to introduce the reader into the study area. It presents general and brief information about the municipality of Puerto Berrío and the Magdalena region, in order to provide spatial orientation as well as some demographic and climatic information. The second and third section of the chapter present the institutional and legal framework related to water quality issues.
- 1 Regional and local background
- 2 Institutional framework
- 3 Legal framework on water quality
Regional and local background
Section keywords: location, population, climate, economic activities, river extension, main characteristics, ecology, importance, navigability
The municipality of Puerto Berrío is located in Colombia, in the department of Antioquia. It is found on a flood plain that belongs to the Middle Magdalena region, called this way because of the presence of the Magdalena River, the main river of the country. A total of six municipalities of the department of Antioquia are part of this region, and four of them are located on the riverside, including Puerto Berrío (see Figure 1), at an elevation above sea level of 125 m. Puerto Berrío was founded in 1875 and nowadays has an extension of 1,184 Km2 (Gobernación de Antioquia, 2007) with a population of 48,802 inhabitants (Alcaldía Municipal de Puerto Berrío, 2008), from which 88% is located in the urban area. The municipality is of great importance thanks to the harbor at the Magdalena River, which is an important transport and communication way for the center of the country. The Magdalena River has a length of 1,528 km (Cormagdalena, 2007) and crosses the country from south to north, flowing into the Caribbean Sea, constituting the main navigable artery of the country. The economic activities of Puerto Berrío are mainly the commerce, cattle farming and agricultural crops such as lemon and manioc (Gobernación de Antioquia, 2007 and Alcaldía Municipal de Puerto Berrío, 2008).
Figure 1 Location of Puerto Berrío in the country and the region
Location of: a) Department of Antioquia in Colombia b) Middle Magdalena region in Antioquia c) Puerto Berrío in the Middle Magdalena Region
The climate in the territory is warm and influenced by the presence of the river, with a mean annual temperature of 28.4ºC, being the first months of the year the warmest and the last ones the coldest. The precipitation has a bimodal distribution, i.e., there are two rainy seasons in the year, namely in April and September, being December and January the driest months. The annual mean precipitation is 2,399.3 mm (see Appendix E). Puerto Berrío has a very humid climate, with relative humidity that ranges from 66% in February to 90% in July. This high humidity is a consequence of the also high evaporation in the territory, which at the same time depends on the wind velocity, not higher than 5 Km/h, the temperature and the solar radiation. In Puerto Berrío, the mean annual evaporation is 1,414.5 mm (Alcaldía Municipal de Puerto Berrío, 2000).
Section keywords: Cormagdalena, Corantioquia, Aguas del Puerto S.A., Conhydra, Oficina de Planeación, ISAGEN, IDEA, IDEAM, Inst. Geográfico Agustín Codazzi, MAVDT, Departamentos de Ing. Ambiental diversas universidades.
The present section gives an overview of the institutions, both governmental and non-governmental, that are related in some way to environmental, and more specific, to water quality issues in the study area. It includes institutions at the national, regional and local level.
Ministerio de Ambiente, Vivienda y Desarrollo Terriotrial, MAVDT
The MAVDT is the Ministry of Environment, Housing and Territorial Development and it is the governing national public entity in the environmental, housing, territorial development, drinking water and sanitation matters, that contributes and promotes actions oriented to a sustainable development, through the formulation, adoption and technical and legislative implementation of policies, following the principles of participation and public management integrity (MAVDT, 2007). 
Instituto de Hidrología, Meteorología y Estudios Ambientales de Colombia, IDEAM
The IDEAM is the Institute of Hydrology, Meteorology and Environmental Studies for the national territory in Colombia. Its function is to generate knowledge and produce and provide data and environmental information besides carrying out studies, research, inventories and activities for the monitoring and management of information, that serve as a base for decision making in environmental policy matters and for the use and management of the bio-physical natural resources of the country (IDEAM, 2001). 
Corantioquia, the Autonomous Corporation for the Center of Antioquia is a national, public, corporative entity, with financial and administrative autonomy. It comprises 80 municipalities, including those of the Middle Magdalena region located in the department of Antioquia. It is its duty to administrate the renewable natural resources and to issue environmental permissions for their use, and also to regulate the activities that may affect the environment. This entity carries out policies, plans, programs and projects related to the environment and the renewable natural resources and it cares for the fulfillment of the legislation issued by the Ministry of Environment (Corantioquia, 2005). 
Also called “Regional Autonomous Corporation of the Magdalena River”, Cormagdalena is a special national corporative body with its own budget and administrative and financial autonomy. The main objective of the corporation is the recovery of the navigability and port activities of the Magdalena River, as well as land conservation, energy generation and distribution, and the sustainable use and preservation of the environment and the renewable natural resources. The jurisdiction of Cormagdalena includes all municipalities located at the riverside of the Magdalena River from its start in the southern part of the country until its end in the Caribbean coast (Cormagdalena, 2008). 
Mayoralty of Puerto Berrío
Among the many functions of the Mayoralty of Puerto Berrío, this governmental body must establish mechanisms for the planning and sustainable development of the municipality and care for the integral development of the community and its most vulnerable groups. These are the most relevant functions regarding the present work, as well as the functions of the Planning Secretary, a dependency of the Mayoralty. This office must present development and investment projects and programs to the Municipal Council and is also in charge of the preparation and formulation of the Land Use Plan, the Development Plan and other sectorial plans of the municipality (Puerto Berrío, 2008). 
Aguas del Puerto S.A.
Aguas del Puerto S.A. is the company in charge of the drinking water supply and the sewage system for the municipality of Puerto Berrío and must guarantee quality and efficiency and improve the coverage and continuity of the service (Puerto Berrío, 2008).
Neotrópicos is an environmental, non-governmental organization located in the city of Medellín, the capital of the department of Antioquia. The objectives of the organization are to promote and spread the knowledge, research, recovery, restoration, conservation and rational use of the neo-tropical ecosystems. The main activities of Neotrópicos are focused on the restoration and conservation of the Mompox flood plain, located at the riverside of the Magdalena River, downstream of Puerto Berrío (Neotrópicos, 2008). This institution, involved in several projects in the Magdalena River, provided important information and guidance for the realization of the present study. 
Legal framework on water quality
Following are the laws, decrees and guidelines related to water quality in the country:
Law 09 from 1979
This law establishes sanitary measures, including the different uses of the water such as human consumption, domestic, flora and fauna preservation, recreation, agriculture, industry and the regulations for the protection of the water sources (Congreso de Colombia, 1979).
Law 99 from 1993
With this law the Ministry of Environment was created, the public sector in charge of the management and conservation of the environment and the renewable natural resources was rearranged and the National Environmental System was organized. All regional autonomous corporations were created as well, together with the establishment of their functions, according to which these entities are the environmental authorities within their jurisdiction and must care for the conservation of the environment and the fulfillment of the legislation in that matter. In this law it was also determined that there will be charges for the use of the land, water bodies or atmosphere for the discharge of waste, and that they will be paid to the regional autonomous corporations (Congreso de Colombia, 1993).
Decree 1594 from 1984
This decree regulates the use of water and the liquid waste. According to the uses defined in the Law 09 from 1979, this decree sets the water quality parameters to be considered. In order to determine the most adequate destination of the water, this decree states, among others, that water quality models should be use as a tool for managing water resources in order to determine their capacity of assimilating and diluting the substances discharged in them, and for the use of these simulation models, the responsible environmental authority must monitor at least the following water quality parameters: BOD, COD, suspended solids, pH, temperature, dissolved oxygen, discharge, hydro-biological data and coliform bacteria. This decree also presents the equation for the calculation of the maximum daily loads permitted for the substances to be regulated by the environmental authority (Ministerio de Salud, 1984).
Decree 3100 from 2003
This decree focuses on the regulation of the wastewater charges caused by the use of water resources as receiving bodies for point discharges (MAVDT, 2003).
Decree 3440 from 2004
The decree 3440 gives an improved definition to the water resources decontamination projects. It states that this kind of projects include all investments aimed to the improvement of the physical, chemical and/or bacteriological quality of the discharges or the water bodies and investments for interceptors, final emissaries and wastewater treatment systems (MAVDT, 2004).
Reglamento técnico para el sector de agua potable y saneamiento básico, RAS
The technical guideline for the drinking water and basic sanitation sector was approved in the year 2000 by the Ministry of Economic Development. The RAS gives the technical guidelines for the designs, construction works and procedures related to the drinking water and sanitation sector at the national level (Ministerio de Desarrollo Económico, 1984).